Metal vapor rectifier for heavy currents



Jan. 2, 1934- F. B. VON KLEIST 1,942,317

METAL VAPOR RECTIFIER FOR HEAVY CURRENTS Filed Sept. 22. 1931 WITNESSES:INVENTOR 55 tral cathode 2.

Patented Jan. 2, 1934 PATEN OFFICE METAL VAPOR RECTIFIER FOR HEAVYCURRENTS Felix Baron von Klcist, Berlin-Siemensstadt, Germany, assignorto Westinghcuse Electric &

Manufacturing Company,

Pennsylvania Application September 22,

a corporation of 1931, Serial No.

564,312, and in Germany September 25, 1930 3 Claims.

My invention relates to metal-vapor rectifiers for heavy currents andparticularly to polyphase rectifiers having a plurality of anodes perphase.

Certain difficulties are usually encountered in 5 designing largerectifiers of the type just mentioned, in connection with the fact thatthe anodes must be so arranged that during operation of the rectifier,they will not interfere with each other. For this reason largerectifiers of standard construction provide large distances between theanodes, also it has been proposed to arrange the anodes not in just onecircle, but in several circles, in order to prevent an excessivediameter of the rectifier tank.

But an arrangement providing several anode circles has also certaindisadvantages. And even from an electrical standpoint trouble will beexperienced, because of the fact that the arcs cannot develop uniformlybetween the individual anodes and the cathode; the arcs will be ofdifferent lengths and consequently will not have the same voltage drop.

This invention constitutes a solution of the problem of how to properlyarrange a large number of anodes in a rectifier tank; this solutionconsists in placing the anodes, belonging to the same phase, closelytogether. It is very desirable to arrange all anodes on one commoncircle, and to place the anodes belonging to the same phase closelytogether.

According to my invention all the anodes belonging to one phase aregrouped'as closely together as is mechanically possible, while the phasegroups are widely separated from each other. Since there is nodiiierence of potential between the anode of the same phase, in fact ifdesirable, the anodes may be on a common anode stern, there is no dangerof breakdown between the closely spaced anodes while the phase groups 40are spaced sufliciently to prevent breakdown between phases.

The closely spaced anodes according to my invention are enclosed in acommon shield so that the anodes of each phase are shielded as a unit.

Other objects and advantages of my invention will be apparent from thefollowing detailed description taken in conjunction with theaccompanying drawing, in which Figure l is a schematic plan view of arectifier embodying my invention, and

Fig. 2 is a sectional elevation of an anode group with its accompanyingshield.

The apparatus, as disclosed, comprises a container 1 preferably of metalin which is a cen- Arranged in a single circle in the rectifier tank area plurality of anodes 3. These anodes are connected to any suitablepolyphase source of supply, each phase of the supply being connected toa plurality of parallel connected anodes All of the parallel connectedanodes of one phase, may, if desired, be placed on a single anode stemor, if desirable, for reasons of current distribution, between the anodeheads, each individual head may have a separate stem extending outsideof the tank for connection with a suitable current divider. In eithercase the anodes 3 connected to the same phase are placed as closetogether as is mechanically convenient. However, the groups of anodesbelonging to the individual phases are widely spaced from each other.

Each phase group of anodes is provided with a shield 4 adapted tosubstantially enclose all of the anodes 3 of the group and being commonto all the said anodes.

Preferably each of the shields 4 is provided with a grid 6 common to allof the anodes'of the phase group enclosed in the shield. Although anytype of grid may be used, I prefer to use a grid substantially closedexcept for are passages 7 substantially opposite the anode faces.

In order to more completely shield the anodes, I have provided theshield 4 with transverse partitions 8 for separating the arc streamsproceeding from the individual anode heads. While these partitions maybe of any desired length, I have found it sufiicient to place thesepartitions 8 only in the open end of the shield extending up to thevicinity of the grid 6.

In operation the rectifier of my invention is substantially similar tothe operation of other plural anodes, and rectifiers, except that all ofthe active anodes are grouped together and enclosed in a common shield.These active anodes being at a common potential there is no danger ofbreakdown between the active anodes. Furthermore, by placing the anodesactive at any one time in closely spaced relation, it is possible tosecure a maximum spacing between the anode groups with minimum spacingbetween the anodes, thus securing the advantage of a multiplicity ofactive anodes as well as the advantage of small tank size.

While I have shown and described the specific modifications of myinvention, it is apparent that many changes and modifications could bemade therein without departing from the spirit and scope of myinvention. I desire, therefore, that only such limitations shall beimposed as 110 each phase being closely grouped but spaced from theanode of every other phase, a shield surrounding each phase group, agrid in each of said shields, and partitions in the shields.

3. A vapor-electric device-comprising a metal tank, a cathode in thetank, a plurality of anodes in the tank, said anodes being arranged ingroups having the anodes of a group closely spaced to each other, saidgroups having greater spacing than the anodes; of the group, a shieldfor each group of anodes and a grid in the shield, said shield beingcommon to all anodes of the group.

FELIX BARON VON KLEIST.

